Thin film transistor array panel and liquid crystal display including the panel

ABSTRACT

A thin film transistor array panel is provided, which includes: a plurality of gate lines formed on a substrate and including a plurality of oblique portions and a plurality of gate electrodes; a first insulating layer on the gate line; a semiconductor layer formed on the first insulating layer; a plurality of data lines formed at least on the semiconductor layer and intersecting the gate lines to defined trapezoidal pixel areas; a plurality of drain electrodes separated from the data lines; a second insulating layer formed at least on portions of the semiconductor layer that are not covered with the data lines and the drain electrodes; a plurality of pixel electrodes formed on the second insulating layer and connected to the drain electrodes, at least two of the pixel electrodes disposed in each pixel area; and a plurality of common electrodes formed on the second insulating layer, arranged alternate to the pixel electrodes and connected to the drain electrodes, each common electrode having an edge spaced apart from an edge of the pixel electrodes and substantially parallel to the edge of the pixel electrodes.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a thin film transistor array panel fora liquid crystal display, and in particular, to a thin film transistorarray panel including two kind of field-generating electrodes forgenerating horizontal electric field.

(b) Description of the Related Art

A conventional art for driving liquid crystal by using horizontalelectric field is disclosed in U.S. Pat. No. 5,598,285.

A liquid crystal display (LCD) disclosed in U.S. Pat. No. 5,598,285includes pixel electrodes and common electrodes for generatinghorizontal electric field. The LCD has a problem that the behaviors ofthe liquid crystal molecules are distorted near top and bottom portionsof a pixel, where the common electrodes and a storage electrode lineconnected to the common electrodes for transmitting a common signal areadjacent to each other. The distortion may be covered by widening ablack matrix, but it reduces the aperture ratio.

In addition, there is a problem that the coupling between a data linefor applying voltages to the pixel electrodes and the pixel electrodesor the common electrodes parallel to the data line distorts the liquidcrystal driving to cause light leakage and crosstalk. This problem maybe solved by widening the common electrodes adjacent to the data line,but it also reduces the aperture ratio.

Furthermore, it is difficult to increase the number of the electrodessince the common electrodes and the pixel electrodes extend parallel tothe data line, i.e., parallel to long edges of a pixel defined by gatelines and the data lines.

SUMMARY OF THE INVENTION

A thin film transistor array panel is provided, which includes: aplurality of gate lines formed on a substrate and including a pluralityof oblique portions and a plurality of gate electrodes; a firstinsulating layer on the gate line; a semiconductor layer formed on thefirst insulating layer; a plurality of data lines formed at least on thesemiconductor layer and intersecting the gate lines to definedtrapezoidal pixel areas; a plurality of drain electrodes separated fromthe data lines; a second insulating layer formed at least on portions ofthe semiconductor layer that are not covered with the data lines and thedrain electrodes; a plurality of pixel electrodes formed on the secondinsulating layer and connected to the drain electrodes, at least two ofthe pixel electrodes disposed in each pixel area; and a plurality ofcommon electrodes formed on the second insulating layer, arrangedalternate to the pixel electrodes and connected to the drain electrodes,each common electrode having an edge spaced apart from an edge of thepixel electrodes and substantially parallel to the edge of the pixelelectrodes.

The gate lines may be curved near boundaries of the pixel areas.

The common electrodes and the pixel electrodes may extend substantiallyparallel to the oblique portions of the gate lines.

The thin film transistor array panel may further include a plurality ofstorage electrode lines having a plurality of first portions extendingsubstantially parallel to the data lines.

The thin film transistor array panel may further include a plurality ofsignal lines overlapping the storage electrode lines to form storagecapacitors.

The pixel electrodes and the common electrodes may include transparentmaterial.

The thin film transistor array panel may further include a plurality ofcolor filters disposed under the passivation layer and in the pixelareas.

A liquid crystal display is provided, which includes: a first panel; asecond panel facing the first panel; and a liquid crystal layerinterposed between the first panel and the second panel. The first panelincludes: a plurality of gate lines formed on a substrate and includinga plurality of oblique portions and a plurality of gate electrodes; afirst insulating layer on the gate line; a semiconductor layer formed onthe first insulating layer; a plurality of data lines formed at least onthe semiconductor layer and intersecting the gate lines to definedtrapezoidal pixel areas; a plurality of drain electrodes separated fromthe data lines; a second insulating layer formed at least on portions ofthe semiconductor layer that are not covered with the data lines and thedrain electrodes; a plurality of pixel electrodes formed on the secondinsulating layer and connected to the drain electrodes, at least two ofthe pixel electrodes disposed in each pixel area; and a plurality ofcommon electrodes formed on the second insulating layer, arrangedalternate to the pixel electrodes and connected to the drain electrodes,each common electrode having an edge spaced apart from an edge of thepixel electrodes and substantially parallel to the edge of the pixelelectrodes.

The liquid crystal display may further include a sealant disposed aroundthe second panel and confining the liquid crystal layer.

The liquid crystal display may further include a light blocking memberlocated within the sealant and defining a display area for displayingimages.

The light blocking member may include organic material and it ispatterned by photolithography.

The liquid crystal display may further include a plurality of spacersincluding the same layer as the light blocking member.

The spacers may have a height different from the light blocking member.

The light blocking member may have a plurality of depressions.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more apparent by describingembodiments thereof in detail with reference to the accompanyingdrawings in which:

FIG. 1 is a schematic plan view of an LCD according to an embodiment ofthe invention;

FIG. 2 is a sectional view of the LCD shown in FIG. 1 taken along theline II-II′.

FIG. 3 is a schematic layout view of a pixel in a TFT array panel for anLCD according to an embodiment of the present invention;

FIG. 4 is a sectional view of the TFT array panel shown in FIG. 3 takenalong the line IV-IV′;

FIGS. 5A, 6A, 7A, 8A and 9A are layout views of the TFT array panelshown in FIGS. 3 and 4 in intermediate steps of a manufacturing methodthereof according to an embodiment of the present invention;

FIGS. 5B, 6B, 7B, 8B and 9B are sectional views of the TFT array panelshown in FIGS. 5A, 6A, 7A, 8A and 9A taken along the lines VB-VB′,VIB-VIB′, VIIB-VIIB′, VIIIB-VIIIB′, IX-IX′, respectively;

FIG. 10 is a sectional view of an exemplary TFT array panel for an LCDaccording to another embodiment of the present invention;

FIG. 11 is a sectional view of an exemplary TFT array panel for an LCDaccording to another embodiment of the present invention;

FIG. 12 is a schematic layout view of an LCD according to an embodimentof the present invention; and

FIGS. 13 and 14 are sectional views of the opposite panel of the LCDshown in FIG. 12 taken along the lines XIII-XIII′ and XIV-XIV′,respectively.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention now will be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the invention are shown. The present invention may, however, beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein.

In the drawings, the thickness of layers, films and regions areexaggerated for clarity. Like numerals refer to like elementsthroughout. It will be understood that when an element such as a layer,film, region or substrate is referred to as being “on” another element,it can be directly on the other element or intervening elements may alsobe present. In contrast, when an element is referred to as being“directly on” another element, there are no intervening elementspresent.

Now, liquid crystal displays (LCDs) and thin film transistor (TFT) arraypanels therefor according to embodiments of the present invention willbe described with reference to the accompanying drawings.

An LCD according to an embodiment of the invention is described indetail with reference to FIGS. 1 and 2.

FIG. 1 is a schematic plan view of an LCD according to an embodiment ofthe invention, and FIG. 2 is a sectional view of the LCD shown in FIG. 1taken along the line II-II′.

Referring to FIGS. 1 and 2, an LCD according to an embodiment of theinvention includes lower and upper panels 100 and 200 facing each otherand interposing a gap therebetween, a liquid crystal layer 300 filled inthe gap between the lower panel 100 and the upper panel 200 andincluding a plurality of liquid crystal molecules that are alignedsubstantially parallel to surfaces of the panels 100 and 200, a sealant400 interposed between the lower panel 100 and the upper panel 200 andsealing the liquid crystal layer, and a light blocking layer 500 (whichis called a “black matrix”) disposed within the sealant 400, defining adisplay area displaying images, and blocking light leakage around thedisplay area. The light blocking layer 500 is preferably made of organicmaterial and it may have a function of a spacer sustaining the gapbetween the panels 100 and 200.

When manufacturing the LCD, the light blocking layer 500 and the sealant400 are formed on the upper panel 200, which is also called an oppositepanel, and a plurality of signal lines and a plurality of TFTs areformed on the lower panel 100, which is also called a TFT array panel.Both or either of the light blocking layer 500 and the sealant 400 maybe formed on the TFT array panel 100.

In detail, a plurality of gate lines and a plurality of data linesdefining a plurality of pixel areas having a shape of trapezoid areprovided on the TFT array panel 100 and a plurality of pixel electrodesand common electrodes are aligned in parallel to each other. A pluralityof storage electrode lines connected to the common electrodes extendparallel to the data lines and to the long edges of the pixel areas.Liquid crystal molecules are aligned perpendicular to the data lines andthe common signals lines in absence of electric field, and the gatelines include a plurality of transverse portions intersecting the datalines and a plurality of oblique portions extending parallel to thecommon electrodes.

First, a TFT array panel for an LCD according to a first embodiment ofthe present invention is now described with reference to FIGS. 3 and 4.

FIG. 3 is a schematic layout view of a pixel in a TFT array panel for anLCD according to an embodiment of the present invention, and FIG. 4 is asectional view of the TFT array panel shown in FIG. 3 taken along theline IV-IV′.

Referring to FIGS. 3 and 4, a plurality of gate lines 121 and aplurality of storage electrode lines 131 separated from the gate lines121 are formed on an insulating substrate 110.

The gate lines 121 for transmitting gate signals extend substantially ina transverse direction and are separated from each other. A plurality ofportions of each gate line 121 form gate electrodes 123, but the gateelectrodes 123 may be branched from the gate lines 121. Each gate line121 includes a plurality of oblique portions and a plurality oftransverse portions connected alternately. The oblique portions includerising portions and falling portions from the left to the right and theyare alternately arranged in the transverse direction and a longitudinaldirection. Each gate line 121 may include an end portion (not shown) forcontact with another layer or an external device. The gate electrodes123 may be branched from the gate lines 121.

Each storage electrode line 131 extends substantially in the transversedirection and it is substantially equidistant from adjacent two gatelines 121. Each storage electrode line 131 includes a plurality oflongitudinal branches 132 extending upward and downward and a pluralityof expansions 134 having large areas. Each expansion 134 has a risingedge and a falling edge from the left to the right, which aresubstantially parallel to the rising portions and the falling portionsof the gate lines 121. The rising edges face the rising portions of thegate lines 121 and the falling edges face the falling portions of thegate lines 121. The storage electrode lines 131 are supplied with apredetermined voltage such as a common voltage.

The gate lines 121 and the storage electrode lines 131 are preferablymade of Al and Al alloy, Ag containing metal such as Ag and Ag alloy, Cucontaining metal such as Cu and Cu alloy, Cr, Mo, Mo alloy, Ta, or Ti.They may have a multi-layered structure. The gate lines 121 and thestorage electrode lines 131 may include two films having differentphysical characteristics, a lower film and an upper film. The upper filmare preferably made of low resistivity metal including Al containingmetal such as Al and Al alloy for reducing signal delay or voltage dropin the gate lines 121 and the storage electrode lines 131. On the otherhand, the lower film is preferably made of material such as Cr, Mo, Moalloy, Ta and Ti, which has good physical, chemical, and electricalcontact characteristics with other materials such as indium tin oxide(ITO) and indium zinc oxide (IZO). A good exemplary combination of thelower film material and the upper film material is Cr and Al-Nd alloy.

In addition, the lateral sides of the gate lines 121 and the storageelectrode lines 131 are inclined relative to a surface of the substrate110, and the inclination angle thereof ranges about 20-80 degrees.

A gate insulating layer 140 preferably made of silicon nitride (SiNx) isformed on the gate lines 121 and storage electrode lines 131.

A plurality of semiconductor islands 150 preferably made of hydrogenatedamorphus silicon (abbreviated to “a-Si ”) or polysilicon are formed onthe gate insulating layer 140 and disposed opposite the gate electrodes123. A plurality of pairs of ohmic contacts 163 and 165 preferably madeof silicide or n+hydrogenated a-Si heavily doped with n type impurityare formed on the semiconductor islands 150. Each pair of ohmic contacts163 and 165 are located on the semiconductor islands 150. Thesemiconductor islands 150 and the ohmic contacts 163 may extend in thelongitudinal direction.

The lateral sides of the semiconductor islands 151 and the ohmiccontacts 163 and 165 are inclined relative to a surface of the substrate10, and the inclination angles thereof are preferably in a range betweenabout 30-80 degrees.

A plurality of data lines 171 and a plurality of drain electrodes 175are formed on the ohmic contacts 163 and 165 and the gate insulatinglayer 140.

The data lines 171 transmitting data voltages extend substantially inthe longitudinal direction and intersect the gate lines 121 to definethe trapezoidal pixel areas. Each data line 171 may include an endportion (not shown) for contact with another layer or an externaldevice.

A plurality of branches of each data line 171 extend onto the ohmiccontacts 163 to form a plurality of source electrodes 173 facing endportions of the drain electrodes 175. Each pair of the source electrodes173 and the drain electrodes 175 are separated from each other andopposite each other with respect to a gate electrode 123. A gateelectrode 123, a source electrode 173, and a drain electrode 175 alongwith a semiconductor island 154 form a TFT having a channel formed inthe semiconductor island 150 disposed between the source electrode 173and the drain electrode 175.

Each drain electrode 175 includes a longitudinal portion 172 extendingfrom an ohmic contact 165 in the longitudinal direction to overlap abranch 132 of a storage electrode line 131 and a transverse portion 176extending in the transverse direction to overlap the storage electrodelines 131. The transverse portion 176 has an expansion 174 overlappingan expansion 134 of a storage electrode line 131 and havingsubstantially the same planar shape as the expansion 134.

The data lines 171 and the drain electrodes 175 are preferably made ofrefractory metal such as Cr, Mo, Mo alloy, Ta or Ta. They may include alower film preferably made of Mo, Mo alloy or Cr and an upper filmlocated thereon and preferably made of Al containing metal or Agcontaining metal.

Like the gate lines 121 and the storage electrode lines 131, the datalines 171 and the drain electrodes 175 have tapered lateral sidesrelative to the surface of the substrate 110, and the inclination anglesthereof range about 30-80 degrees.

The ohmic contacts 163 and 165 are interposed only between theunderlying semiconductor islands 150 and the overlying data lines 171and the overlying drain electrodes 175 thereon and reduce the contactresistance therebetween. The semiconductor islands 150 include aplurality of exposed portions, which are not covered with the data lines171 and the drain electrodes 175, such as portions located between thesource electrodes 173 and the drain electrodes 175.

A plurality of red, green and blue color filters R, G and B is formed onthe data lines 171, the drain electrodes 175, and the exposed portionsof the semiconductor stripes 151. Each of the color filters R, G and Bare disposed substantially between adjacent two the data lines 171 andextends in a longitudinal direction. The color filters R, G and B arenot disposed on a peripheral area which is provided with the endportions of the gate lines 121 and the data lines 171. Although FIG. 4shows that edges of adjacent color filters R, G and B exactly match eachother, the color filters R, G and B may be spaced apart from each other.The color filters R, G and B may overlap each other on the data lines171 to block the light leakage and, in this case, their edges arepreferably inclined relative to the surface of the substrate.

An interlayer insulating layer (not shown) preferably made of inorganicinsulating material such as silicon oxide or silicon nitride may bedisposed under the color filters R, G and B.

A passivation layer 180 is formed on the color filters R, G and B. Thepassivation layer 180 is preferably made of silicon nitride or organicmaterial having a good flatness characteristic.

The passivation layer 180 and the color filters R, G and B have aplurality of triple contact holes 182 exposing the longitudinal portions172 of the drain electrodes 175. In addition, the passivation layer 180and the color filters R, G and B may have a plurality of contact holes(not shown) exposing the end portions of the gate lines 121 and the datalines 171.

A plurality of pixel electrodes 192 and 194 and a common electrode netincluding a plurality of longitudinal stems and a plurality of commonelectrodes 191, 193 and 195 connected to at least one of adjacentlongitudinal stems are formed on the passivation layer 180. The pixelelectrodes 192 and 194 and the common electrode net may be made oftransparent conductive material such as ITO and IZO in order to increasethe transmittance of light.

The pixel electrodes 192 and 194 are physically and electricallyconnected to the longitudinal portions of the drain electrodes 175through the contact holes 182 such that the pixel electrodes 190 receivethe data voltages from the drain electrodes 175. Each pixel electrode194 overlaps an expansion 134 of a storage electrode line 131 as well asan expansion 174 of a drain electrode 175 and includes two branches 196extending substantially parallel to the rising edge and the falling ofthe expansion 134, respectively. (For descriptive convenience, thebranches 196 are also referred to as pixel electrodes.) Each pixelelectrode 192 that is substantially rectilinear is disposed between anoblique portion of a gate line 121 and a pixel electrode 196 and extendssubstantially parallel thereto.

Each common electrode 195 is connected to one longitudinal stem andoverlaps a storage electrodes line 131. The common electrode 195 isdisposed between the branches 196 of a pixel electrode 194 and has arising edge and a falling edge parallel to the branches 196. Each commonelectrode 191 is connected to adjacent longitudinal stems and covers anoblique portion of a gate line 121 such that both edges of the commonelectrode 191 are disposed opposite each other with respect to the gateline 121 and extend parallel to the oblique portion. Each commonelectrode 193, which is substantially rectilinear, is disposed betweenadjacent pixel electrodes 192 and 196 and extends substantially parallelthereto.

Accordingly, the common electrodes 191, 193 and 195 and the pixelelectrodes 192 and 196 are alternately arranged and edges of the commonelectrodes 191, 193 and 195 and the pixel electrodes 192 and 196 aresubstantially parallel to each other.

The pixel electrodes 192 and 196 connected to a drain electrode 175 andthe common electrodes 191, 193 and 195 adjacent thereto form a liquidcrystal capacitor, which stores applied voltages after turn-off of theTFT. An additional capacitor called a “storage capacitor,” which isconnected in parallel to the liquid crystal capacitor, is provided forenhancing the voltage storing capacity. The storage capacitors areimplemented by overlapping the pixel electrodes 192 and 194 with thestorage electrode lines 131. The capacitances of the storage capacitors,i.e., the storage capacitances are increased by extending andoverlapping the drain electrodes 175, which are connected to and locatedunder the pixel electrodes 192 and 194, to/with the storage electrodelines 131 for decreasing the distance between the terminals and byproviding the expansions at the drain electrodes 175 and the storageelectrode lines 131 for increasing overlapping areas.

A plurality of contact assistants (not shown) may be formed on thepassivation layer 180 and they may be connected to the end portions ofthe gate lines 121 and the data lines 171 through the contact holesprovided at the passivation layer 180 and the color filters R, G and B.

An alignment layer (not shown) for aligning liquid crystal molecules isformed on the passivation layer 180. The alignment layer may be rubbedpreferably in a direction perpendicular to the data lines 171.

The common electrodes 191, 193 and 195 and the pixel electrodes 192 and194 may be formed of the same layer as the gate lines 121 and the datalines 171, respectively. The common electrode 191, 193 and 195 and thepixel electrodes 192 and 196 preferably have thickness equal to or lessthan about 2,000 Å for preventing alignment defect due to heightdifference.

In the TFT array panel for an LCD according to this embodiment of thepresent invention, the color filters R, G and B and the passivationlayer 180 made of low dielectric organic material and interposed betweenthe electrodes 191, 192, 193, 196 and 195 and the gate lines 121 and thedata lines 171 weaken the lateral field therebetween and thus theelectrodes 191, 192, 193, 196 and 195 can overlap the gate lines 121 andthe data lines 171 to increase the aperture ratio.

In addition, the color filters R, G and B disposed on the TFT arraypanel 100 can reduce the alignment margin to prevent the reduction ofthe aperture ratio.

Moreover, the longitudinal branches 132 of the storage electrode lines131 extend parallel to the data lines 171 along long edges of the pixelareas and the rubbing direction is determined such that the liquidcrystal molecules are aligned perpendicular to the data lines 171 inabsence of electric field. Accordingly, an electric field generated bythe voltage difference between the data lines 171 and the longitudinalbranches 132 of the storage electrode lines 131 makes the liquid crystalmolecules be in their initial orientations and the corresponding areasare displayed dark to prevent lateral crosstalk.

In addition, the number of the electrodes 191, 192, 193, 196 and 195 canbe easily adjusted since the common electrodes 191, 193 and 195 and thepixel electrodes 192 and 196 are arranged in a long edge direction ofthe pixel areas unlike the conventional art.

Furthermore, the effective display area can be enlarged to corners ofthe pixel areas since the pixel electrodes and the common electrodeslocated near the edges of the pixel areas extend parallel to the edgesof the pixel areas defined by the gate lines 121 and the data lines 171.Moreover, the storage capacitors located near the centers of the pixelareas, where the textures are generated to deteriorate image quality,prevent the reduction of the transmittance of the pixel areas tomaximize the transmittance of the pixel areas.

A method of manufacturing the TFT array panel shown in FIGS. 3 and 4according to an embodiment of the present invention will be nowdescribed in detail with reference to FIGS. 5A to 9B as well as FIGS. 3and 4.

FIGS. 5A, 6A, 7A, 8A and 9A are layout views of the TFT array panelshown in FIGS. 3 and 4 in intermediate steps of a manufacturing methodthereof according to an embodiment of the present invention, and FIGS.5B, 6B, 7B, 8B and 9B are sectional views of the TFT array panel shownin FIGS. 5A, 6A, 7A, 8A and 9A taken along the lines VB-VB′, VIB-VIB′,VIIB-VIIB′, VIIIB-VIIIB′, IX-IX′, respectively.

Referring to FIGS. 5A and 5B, a plurality of gate lines 121 including aplurality of gate electrodes 123 and a plurality of storage electrodelines 131 including a plurality of longitudinal branches 132 andexpansions 134 are formed on an insulating substrate 110 byphoto-etching.

Referring to FIGS. 6A and 6B, after sequential deposition of a gateinsulating layer 140, an intrinsic a-Si layer, and an extrinsic a-Silayer, the extrinsic a-Si layer and the intrinsic a-Si layer arephoto-etched to form a plurality of extrinsic semiconductor islands 160and a plurality of intrinsic semiconductor islands 150 on the gateinsulating layer 140.

Referring to FIGS. 7A and 7B, a plurality of data lines 171 including aplurality of source electrodes 173 and a plurality of drain electrodes175 including a plurality of longitudinal portions 172 and transverseportions 176 having expansions 174 are formed by photo etching.

Thereafter, portions of the extrinsic semiconductor islands 160, whichare not covered with the data lines 171 and the drain electrodes 175 areremoved to complete a plurality of ohmic contact islands 163 and 165 andto expose portions of the intrinsic semiconductor islands stripes 150.Oxygen plasma treatment preferably follows thereafter in order tostabilize the exposed surfaces of the semiconductor islands 150.

As shown in FIGS. 8A and 8B, an interlayer insulating layer (not shown)is formed and photosensitive films including red, green and bluepigments are coated and patterned in sequence to form a plurality ofred, green, and blue color filters R, G, and B having openings exposingthe longitudinal portions 172 of the drain electrodes 175. A passivationlayer 180 is deposited and patterned along with the interlayerinsulating layer and the gate insulating layer 140 to form a pluralityof contact holes 182 having slanted sidewalls.

Finally, as shown in FIGS. 3 and 4, a plurality of pixel electrodes 192and 194, a common electrode net including the common electrodes 191, 193and 195, and a plurality of contact assistants (not shown) are formed onthe passivation layer 180 by depositing and photo-etching an ITO or IZOlayer having a thickness of about 400 Å-500 Å.

A TFT array panel for an LCD according to another embodiment of thepresent invention will be described in detail with reference to FIG. 10.

FIG. 10 is a sectional view of an exemplary TFT array panel for an LCDaccording to another embodiment of the present invention.

As shown in FIGS. 10, a layered structure of a TFT array panel of an LCDaccording to this embodiment is almost the same as that shown in FIG. 4.That is, a plurality of gate lines 121 including a plurality of gateelectrodes 123 and a plurality of storage electrodes lines 131 includinga plurality of longitudinal branches 132 and expansions 134 are formedon a substrate 110, and a gate insulating layer 140, a plurality ofsemiconductor islands 150, and a plurality of ohmic contact islands 163and 165 are sequentially formed thereon. A plurality of data lines 171including a plurality of source electrodes 173 and a plurality of drainelectrodes 175 including a plurality of longitudinal and transverseportions 172 and 176 having expansions 174 are formed on the ohmiccontacts 163 and 165, and a passivation layer 180 is formed thereon. Aplurality of contact holes 182 are provided at the passivation layer 180and the gate insulating layer 140, and a plurality of pixel electrodes192 and 194 and a common electrode net including a plurality of commonelectrodes 191, 193 and 195 are formed on the passivation layer 180.

Different from the TFT array panel shown in FIG. 4, the TFT array panelaccording to this embodiment includes no color filter, The color filtersmay be provided on an opposite panel.

Many of the above-described features of the TFT array panel shown inFIGS. 3 and 4 may be appropriate to the TFT array panel shown in FIG.10.

A TFT array panel for an LCD according to another embodiment of thepresent invention will be described in detail with reference to FIG. 11.

FIG. 11 is a sectional view of an exemplary TFT array panel for an LCDaccording to another embodiment of the present invention.

As shown in FIGS. 11, a layered structure of a TFT array panel of an LCDaccording to this embodiment is almost the same as that shown in FIG. 4.That is, a plurality of gate lines 121 including a plurality of gateelectrodes 123 and a plurality of storage electrodes lines 131 includinga plurality of longitudinal branches 132 and expansions 134 are formedon a substrate 110, and a gate insulating layer 140, a plurality ofsemiconductors 150, and a plurality of ohmic contacts 163 and 165 aresequentially formed thereon. A plurality of data lines 171 including aplurality of source electrodes 173 and a plurality of drain electrodes175 including a plurality of longitudinal and transverse portions 172and 176 having expansions 174 are formed on the ohmic contacts 163 and165, and a plurality of color filters R, G and B and a passivation layer180 is formed thereon. A plurality of contact holes 182 are provided atthe passivation layer 180 and the gate insulating layer 140, and aplurality of pixel electrodes 192 and 194 and a common electrode netincluding a plurality of common electrodes 191, 193 and 195 are formedon the passivation layer 180.

Different from the TFT array panel shown in FIG. 4, the semiconductors150 have almost the same planar shapes as the data lines 171 and thedrain electrodes 175 as well as the underlying ohmic contacts 163 and165, except for the semiconductors 150 where TFTs are provided. That is,the semiconductors 150 include some exposed portions, which are notcovered with the data lines 171 and the drain electrodes 175, such asportions located between the source electrodes 173 and the drainelectrodes 175.

A manufacturing method of the TFT array panel according to an embodimentsimultaneously forms the data lines 171, the drain electrodes 175, thesemiconductors 151, and the ohmic contacts 161 and 165 using onephotolithography process.

A photoresist pattern for the photolithography process hasposition-dependent thickness, and in particular, it has first and secondportions with decreased thickness. The first portions are located onwire areas that will be occupied by the data lines 171 and the drainelectrodes 175 and the second portions are located on channel areas ofTFTs.

The position-dependent thickness of the photoresist is obtained byseveral techniques, for example, by providing translucent areas on theexposure mask as well as transparent areas and light blocking opaqueareas. The translucent areas may have a slit pattern, a lattice pattern,a thin film(s) with intermediate transmittance or intermediatethickness. When using a slit pattern, it is preferable that the width ofthe slits or the distance between the slits is smaller than theresolution of a light exposer used for the photolithography. Anotherexample is to use reflowable photoresist. In detail, once a photoresistpattern made of a reflowable material is formed by using a normalexposure mask only with transparent areas and opaque areas, it issubject to reflow process to flow onto areas without the photoresist,thereby forming thin portions.

As a result, the manufacturing process is simplified by omitting aphotolithography step.

Many of the above-described features of the TFT array panel shown inFIGS. 3 and 4 may be appropriate to the TFT array panel shown in FIG.11.

First, an opposite panel for an LCD according to an embodiment of thepresent invention is now described with reference to FIGS. 12-14.

FIG. 12 is a schematic layout view of an LCD according to an embodimentof the present invention, and FIGS. 13 and 14 are sectional views of theopposite panel of the LCD shown in FIG. 12 taken along the linesXIII-XIII′ and XIV-XIV′, respectively.

Referring to FIGS. 12-14, a sealant 400 for confining a liquid crystallayer, a light blocking layer 500 for blocking light leakage, and aplurality of columnar spacers 550 for sustaining a gap between a TFTarray panel 100 and an opposite panel 200 are formed on an insulatingsubstrate 210.

The sealant 400 extends along the boundary of the substrate 210 and hasinlets for injecting liquid crystal, which will be sealed after theinjection of the liquid crystal.

The light blocking layer 500 and the spacers 550 are preferably made oforganic material containing black pigment. However, they may be made ofmetal or metal oxide.

The light blocking layer 500 is disposed in an area enclosed by thesealant 400 and extends along the sealant to define a display area. Thelight blocking layer 500 has a plurality of depressions 520 disposedopposite the inlets of the sealant 400 for facilitating the injection ofthe liquid crystal. The light blocking layer 500 may further have otherdepressions disposed opposite the depressions 520.

The spacers 550 are disposed in the display area and regularlydistributed. The spacers 550 may have a thickness larger than the lightblocking layer 500 in consideration of the height of the elements formedin the TFT array panel 100. In this case, the light blocking layer 500and the spacers 550 are patterned by using a photo-mask havingtranslucent areas as well as light transmitting transparent areas andlight blocking opaque areas. The translucent areas may have a slitpattern, a lattice pattern, a thin film(s) with intermediatetransmittance or intermediate thickness. In addition, the depressions520 may be formed by using the above-described photo-mask.

This structure facilitates the formation of the opposite panel 200 sincethere is no color filter thereon. In addition, the light blocking layer500 prevents the liquid crystal from directly contacting the sealant400, thereby preventing the contamination of the liquid crystal by thesealant 400.

While the present invention has been described in detail with referenceto the preferred embodiments, those skilled in the art will appreciatethat various modifications and substitutions can be made thereto withoutdeparting from the spirit and scope of the present invention as setforth in the appended claims.

1. A thin film transistor array panel comprising: a plurality of gatelines formed on a substrate and including a plurality of gateelectrodes; a first insulating layer on the gate line; a semiconductorlayer formed on the first insulating layer; a plurality of data linesformed at least on the semiconductor layer; a plurality of drainelectrodes separated from the data lines; a second insulating layerformed at least on portions of the semiconductor layer that are notcovered with the data lines and the drain electrodes and includingorganic material; a plurality of pixel electrodes formed on the secondinsulating layer and connected to the drain electrodes, at least two ofthe pixel electrodes disposed in each pixel area; and a plurality ofcommon electrodes formed on the second insulating layer, and arrangedalternate to the pixel electrodes, each common electrode having an edgespaced apart from an edge of the pixel electrodes and substantiallyparallel to the edge of the pixel electrodes.
 2. The thin filmtransistor array panel of claim 1, wherein the common electrodes ofadjacent pixel areas are connected to each other.
 3. The thin filmtransistor array panel of claim 1, wherein the second insulating layerinclude a plurality of color filters.
 4. The thin film transistor arraypanel of claim 3, wherein the second insulating layer include aninorganic material layer formed under the color filters .
 5. The thinfilm transistor array panel of claim 1, further comprising a pluralityof storage electrode lines having a plurality of first portionsextending substantially parallel to the data lines.
 6. The thin filmtransistor array panel of claim 5, further comprising a plurality ofsignal lines overlapping the storage electrode lines to form storagecapacitors.
 7. The thin film transistor array panel of claim 1, whereinthe pixel electrodes and the common electrodes comprises transparentmaterial.
 8. A liquid crystal display comprising: a first panel; asecond panel facing the first panel; and a liquid crystal layerinterposed between the first panel and the second panel, wherein thefirst panel includes: a plurality of gate lines formed on a substrateand including a plurality of gate electrodes; a first insulating layeron the gate line; a semiconductor layer formed on the first insulatinglayer; a plurality of data lines formed at least on the semiconductorlayer; a plurality of drain electrodes separated from the data lines; asecond insulating layer formed at least on portions of the semiconductorlayer that are not covered with the data lines and the drain electrodesand including organic material; a plurality of pixel electrodes formedon the second insulating layer and connected to the drain electrodes, atleast two of the pixel electrodes disposed in each pixel area; and aplurality of common electrodes formed on the second insulating layer,arranged alternate to the pixel electrodes, each common electrode havingan edge spaced apart from an edge of the pixel electrodes andsubstantially parallel to the edge of the pixel electrodes.
 9. Theliquid crystal display of claim 8, further comprising a sealant disposedaround the second panel and confining the liquid crystal layer.
 10. Theliquid crystal display of claim 9, further comprising a light blockingmember located within the sealant and defining a display area fordisplaying images.
 11. The liquid crystal display of claim 10, whereinthe light blocking member comprises organic material and is patterned byphotolithography.
 12. The liquid crystal display of claim 11, furthercomprising a plurality of spacers including the same layer as the lightblocking member.
 13. The liquid crystal display of claim 12, wherein thespacers have a height different from the light blocking member.
 14. Theliquid crystal display of claim 13, wherein the light blocking memberhas a plurality of depressions.
 15. The liquid crystal display of claim8, wherein the common electrodes of adjacent pixel areas are connectedto each other.
 16. The liquid crystal display of claim 8, wherein thesecond insulating layer include a plurality of color filters.
 17. Thethin film transistor array panel of claim 16, wherein the secondinsulating layer include an inorganic material layer formed under thecolor filters.